For everyone who doesn't know about "ping": that's actually the number of milliseconds it takes a server to return a special "ping" TCP/IP package to your host.
So, there are no servers with "low" or "high" pings as such, it always depends on where you are, where the server is, how busy the connection is, how many hops it takes to get there, what technology you use on your end and so on.
Jo (with her sat link; it is via sat both directions, right?) can't possibly have pings below 2 * 36,000km / 300,000 km/s * 1000, which is roughly 240, as the signal has to travel up to the satellite which is in geostationary orbit in 36,000km distance and back again, and it can't go faster than the speed of light.
So, Jo's server with the lowest ping might have a higher ping than three quarters of the servers on the list of someone playing Runescape at work at the backbone of a major ISP in the U.S., and most probably servers that are "low ping" for Europeans are "high ping" for Americans, and so on.
As Jo probably has the biggest problems and is of great importance, we should have her tell us what is best for her.
(that said, if it doesn't matter at all for her, I'd prefer 106, 54 or 84 - lootshare worlds with pings constantly below 40 for me.)